Reliability evaluation for aircraft engines is difficult because of the scarcity of failure data. But aircraft engine data are available from a variety of sources. Data fusion has the function of maximizing the amount...Reliability evaluation for aircraft engines is difficult because of the scarcity of failure data. But aircraft engine data are available from a variety of sources. Data fusion has the function of maximizing the amount of valu- able information extracted from disparate data sources to obtain the comprehensive reliability knowledge. Consid- ering the degradation failure and the catastrophic failure simultaneously, which are competing risks and can affect the reliability, a reliability evaluation model based on data fusion for aircraft engines is developed, Above the characteristics of the proposed model, reliability evaluation is more feasible than that by only utilizing failure data alone, and is also more accurate than that by only considering single failure mode. Example shows the effective- ness of the proposed model.展开更多
China Economist has continuously carried out surveys among economists and this round of survey focuses on comparison and interactions between China＇s and the United States＇ economies. The result of the survey shows ...China Economist has continuously carried out surveys among economists and this round of survey focuses on comparison and interactions between China＇s and the United States＇ economies. The result of the survey shows that economists are generally optimistic about the outlook of both countries＇economies. Respondents believed that great differences exist in the components of industrial competitiveness of China and the US; while the US leads in terms of talent, creativity, social system, industrial system integrity and financing, cost is the biggest barrier to improvement in US competitiveness. In comparison, China leads in infrastructure, cost competitiveness and government driving force but inadequate technology is the biggest barrier to improvement in China＇s competitiveness. Respondents believed that in the coming 20years, China＇s economic growth will be 5.2% and US growth will be 2.4%. Around 2034, China＇s economic aggregate will equal the US level but it will take over 60 years for China to catch up with the US in terms of per capita GDP. China＇s manufacturing technology will equal the US level around 2045. More than 62% of economists believed that the Trump administration will effectively re-shore manufacturing and the average score they give to Trump＇s ＂first 100 days ＂＂ in office is 76 points. More than 61% of economists considered it unlikely that a serious trade war will break out between China and the US. They generally believed that China and the US cooperate and compete with each other and that China-US trade enjoys great potential to grow. According to the survey, respondents are more confident about China＇s debt sustainability in comparison with the US.展开更多
The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluores...The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluorescence of oxazoles was quenched mainly by the absorption competition and radiationless energy transfer of nitrocompounds. The fluorescence quenching rate constants of nitrobenzene and nitromethane are 3.0×10 10 L·mol -1 ·s -1 and 1.5×10 8 L·mol -1 ·s -1 respectively for POEOP. This remarkable difference was explicated.展开更多
基金Supported by the National Natural Science Foundation of China and Aviation Fund(60879001)the Natural Science Foundation of Jiangsu Province(BK2009378)+1 种基金the Fundamental Research Fund of Nanjing University of Aeronautics and Astronautics(NS2010179)the Qinglan Project of Jiangsu Province~~
文摘Reliability evaluation for aircraft engines is difficult because of the scarcity of failure data. But aircraft engine data are available from a variety of sources. Data fusion has the function of maximizing the amount of valu- able information extracted from disparate data sources to obtain the comprehensive reliability knowledge. Consid- ering the degradation failure and the catastrophic failure simultaneously, which are competing risks and can affect the reliability, a reliability evaluation model based on data fusion for aircraft engines is developed, Above the characteristics of the proposed model, reliability evaluation is more feasible than that by only utilizing failure data alone, and is also more accurate than that by only considering single failure mode. Example shows the effective- ness of the proposed model.
文摘China Economist has continuously carried out surveys among economists and this round of survey focuses on comparison and interactions between China＇s and the United States＇ economies. The result of the survey shows that economists are generally optimistic about the outlook of both countries＇economies. Respondents believed that great differences exist in the components of industrial competitiveness of China and the US; while the US leads in terms of talent, creativity, social system, industrial system integrity and financing, cost is the biggest barrier to improvement in US competitiveness. In comparison, China leads in infrastructure, cost competitiveness and government driving force but inadequate technology is the biggest barrier to improvement in China＇s competitiveness. Respondents believed that in the coming 20years, China＇s economic growth will be 5.2% and US growth will be 2.4%. Around 2034, China＇s economic aggregate will equal the US level but it will take over 60 years for China to catch up with the US in terms of per capita GDP. China＇s manufacturing technology will equal the US level around 2045. More than 62% of economists believed that the Trump administration will effectively re-shore manufacturing and the average score they give to Trump＇s ＂first 100 days ＂＂ in office is 76 points. More than 61% of economists considered it unlikely that a serious trade war will break out between China and the US. They generally believed that China and the US cooperate and compete with each other and that China-US trade enjoys great potential to grow. According to the survey, respondents are more confident about China＇s debt sustainability in comparison with the US.
文摘The mechanism of nitrocompounds quenching of the fluorescence of 5, 5′ dipheny1 2, 2′ bisoxazole (POOP) and trans 1, 2 bis [2 (5 phenyloxazolyl)] ethene (POEOP) has been studied. It was found that the fluorescence of oxazoles was quenched mainly by the absorption competition and radiationless energy transfer of nitrocompounds. The fluorescence quenching rate constants of nitrobenzene and nitromethane are 3.0×10 10 L·mol -1 ·s -1 and 1.5×10 8 L·mol -1 ·s -1 respectively for POEOP. This remarkable difference was explicated.
